Stone-crushing machine



T. G. RENNERFELT.

STONE CRUSHING MACHINE.

APPLICATION FILED JULY 6. 191a.

Patented Nov. 9, 1920.

WITNESSES I .l N V ENTOR 4% w WW UNITED STATES TUBE GUSTAE RENNERFELT, 0F STOOKHOLM, SWEDEN.

STONE-CRUSHING' MACHINE.

Specification of Letters Patent.

Patented Nov. 9, 1920.

Application filed .Tuly'G, 1918. Serial No. 243,649;

To. all whom it may concern:

Be it known that 1, Tone GUs'rAF REN- NERFELT, a subject of the King of Sweden, and resident of Stockholm, in. the city of Stockholm and kingdom of Sweden, have invented certain new and useful Improvements in Stone-Crushing Machines, of which the following is a specification.

My invention relates to improvements in a stone crushing machine of the type in which stones, ore and similar material are crushed between a stationary jaw and a movable jaw to which a swinging or oscillating movementis transmitted from a driving shaft, journaled in the frame of the machine.

As such machines are generally constructed they suffer from the following faults: Their mechanical efliciency is low, frequently less than 50%, they lack a reliable safety arrangement against overload, and their bearings and journals are subjected to considerable wear and heating. The wear and heating of the bearings is a necessary consequence of the low efficiency, since as much as halfof the energy supplied to the machine may be consumed in friction. But the evil in this respect is fre quently increased by the fact that some of the bearings of the machine become exposed to abnormally high pressures for the reason that they are not in accurate alinement the construction of the machine being such that standard machine tools cannot readily be used for the finishing of all the bearings. The object of my invention is to remedy the above mentioned faults and to produce a stone crushing machine of high mechanical efiiciency, having a reliable safety arrange ment against overload and of such construction that all its bearings can be machined into perfect alinement.

My invention is illustrated in the accompanying drawing in which Figure 1 showsia verticalv sectional view of the machine, Fig. 2 is a plan view of a detail referred to in the specification as a segment or thrust bar, F 3 is a cross sectional view along the line of Fig. 2, 4 is a side view of a detailcalled the lever as seen in' the direction of the arrow in Fig. 1, and Fig. 5 is a detail view of a part termed thesafety bolt.

. Referring to the drawing in detail. 2 representsthe frame of the crusher, 3 the stationary crushing plate, and 4 the other crushingplate fastened to the movable jaw 5 whichis journaledlin the frame by means of the shaft '6. A lever formed in two parts 7 and 8, kept together by a hinge 9 and the bolt 10, is fulcrumed in the frame by means of the round bar 11 which is fastened to the part 7 and rests upon the bearing block 12. The upper end of the lever part 8 is connected'through the pin 14 to the pitman 15 which is mounted on the crank 16 formed on the driving shaft which is journaled in bearings connected with the frame. The lower end of the lever part 7 is provided with a pressure transmittting convex rolling face formed as a cylinder of which the axis passes through the point A parallel with the bar 11. A cogshaped projection 17 is aflixed to the part 7 abovethe convex face. 18 represents a pressure transmitting block or segment which by means of the round bar 19 is journa'led in the jaw 5 at a constant distance from the shaft 6. The segment 18 is formed with a cylindrical rolling face, not necessarily concentric with the bar 19. It is also formed with two lugs 20, arranged to rest during the assembling of the machine on corresponding'lugs 29 in the frame for facilitating the mounting of the segment. 21 represents a spring applied between the frame and the jaw andacting so as to press the segment against the convex face of the lever. The bearing of the bar 19 is lubricated' through a port 22, and the bearing of the bar 11 from an oilcup 23. The latter bearing is protected from dust and sand by a shield 24 hinged to the lever 7. A lip 25 projecting from the jaw 5 above the bar 19 serves to protect the bearing of the segment, which is perforated by openings 26 to permit dust and sand to drop through the seg ment. 27 represents abolt or lug extending from the jaw 5 and arranged. to. prevent. the lever part from swinging too far to the left in Fig. 1.

The machine operates in the following manner: The driving shaft to which arflywheel is keyed is put into rotation. by suitable motive power. The motion of the shaft is transmitted through the crank 16 and pitman 15 to the lever'which receives a swinging motion around its fulcrum 11, so that its upper end. oscillates between the positions indicated by 14: and 14'. From. theshort end of the lever the power is transmitted though the convex face to the segment and to the movable jaw, so that stones fed be tween the crushing plates become crushed.

The segment 18 moves then around its=jourv fairly high speed, so that the nal 19 through a very small angle, so that the friction loss at the journal 19 is insignificant. At the line of contact between the segment 18 and the lever 7 there is a true rolling motion,-and therefore no friction loss at all. 1

The machine is intended to be operated at segment 18 must move with an acceleration which is greater than that due to gravity in order that the segment shall not lose proper mesh with the lever. The said proper mesh, or the correct position of the segment relatively to the lever, would not be lost if a certain minimum, pressure could always be maintained between the segment and the lever. But in actual practice this condition cannot be obtained, for the minimum pressure between the segment and the lever depends, not only on the tension of the springs 21, but also on the amount of loose play in the connection between the driving shaft and the lever. The existence of such play will at times cause a lack of proper pressure between the segment and the lever, so that at the moment when the convex face of the lever recedes from the jaw the segment will be a t to lag behind. For this reason the cog 1 is provided in the lever. The cog will come into contact with thesegment and restore it to its proper position when it lags behind the lever by reason of insufficient pressure between thesegment and the lever.

If the machine should become strongly overloaded for instance, by reason of a Sledgehammer, dropped by accident or by intention between the crushing plates, the safety bolt 10 will be pulled off so that the motion of the lower part 7 of the lever will instantly cease, while the upper part8 may continue to move, swinging around the hinge 9 until the flywheel is stopped. When the bolt 10 breaks, the lever part 7 will be moved by the springs 21 so that the hinge 9 swings toward the left in Fig. 1. The bolt 27 is provided in order to prevent the hinge from swinging too far in said direction, and thus to occupy any of the space which is necessary for the unobstructed mo tion of the pitman. It is evident that for this purpose the bolt 27 could just as well be fastened to the frame. instead of to the The safety bolt 10 is shown in detail in Fig. 5, from which appears that it is formed with two hexagon heads of which the larger one is intended for the screwing of the bolt into the hole at the top end of the lever 7, and the smaller one is intended for removing the broken part of the bolt from the hole. Between the two hexagon heads the, bolt is provided with an incision 28 so that its diameter is reduced to proper size, sufficiently large to transmit any legitimate strain, but relatively weaker than any other part of the machine so that it will certainly conditions are fulfilled: the length of the short arm of the lever defined as the perpendicular distance of the fulcrum 11 from the line which passes through the point A and through the point of contact between the segment and the lever shall remain constant for any position of the crank, and the hinge 9 shall be located on the straight line between the bar 11 and the pin 14. The arrangement illustrated in Fig. 1 is such that both of these conditions are substantially filled.

The adjustment of the distance between the crushing-plates is effected by moving the bearing block 12 in the frame and placing fillers of suitable and uniform thickness between the frame and the block. The seat in the frame upon which the bearing block 12 is located must be exactly parallel with the driving shaft, and since this seat cannot readily be finished with ordinary machine tools the frame shown in Fig. 1 is so designed that it admits the milling of the seat by means of a special device mounted upon two round bars which are clamped in the frame 2, one in the bearings for the driving shaft and the other one in the bearings for the shaft 6.

llaving thus described my invention, what I claim is:

1. The combination of a frame, a jaw journaled in the frame, a thrust bar journaled in the jaw at a constant distance from the journal of the jaw, a lever fulcrumed in the frame and formed with a convex face in contact with the thrustbar, a draw spring connection between the frame and the jaw arranged to press the thrustbar against the convex face, and means forv oscillating the lever, the convex face being in rolling contact with the thrustbar. V i

2. The combination of a frame, a jaw journaled in the frame, a thrustbar journaled in the jaw, a lever fulcrumed in the frame and formed with a convex face in rolling contact with the thrustbar, a draw spring connection between the frame and the jaw arranged to press the thrustbar against the convex face, the thrustbar being formed with lugs arranged to rest on corresponding lugs in the frame for faciliconnection between the frame and the jaw arranged to press the thrustbar against the convex face of the lever, the lever being formed with a cog above the thrustbar, and means for oscillating the lever.

4. The combination of a frame, a jaw journaled in the frame, a thrustbar journaled in the jaw, a lever fulcrumed in the frame and formed with a convex face in rolling mesh with the thrustbar, a draw spring connection between the frame and the jaw, a cog carried by the lever for limiting the variation in the mesh between the convex face and the thrustbar, and means for oscillating the lever.

5. The combination of a frame, a jaw journaled in the frame, a lever fulcrumed in the frame and formed with a convex face, a thrustbar journaled in the jaw at con stant distance from the journal of the jaw and formed with a cylindrical face arranged to roll upon the convex face, a draw spring connection between the frame and the jaw, and means for oscillating the lever.

6. The combination of a frame, a jaw journaled in the frame, a lever fulcrumed in the frame and formed with a convex face,

a thrustbar journaled in the jaw at constant distance from the journal of the jaw and formed with a cylindrical face arranged to roll upon the convex face, of the lever means carried by the lever for limiting the variation in mesh between the convex face and the cylindrical face, a draw spring 

